Alright guys, time for another small udpate.
Today I did the following:
- chopped the rear end of the frame
- cut parts of the side of the rear fender
- weld shut the excess holes in the fender
- weld struts to the rear tubing of the frame + top part
- started on the seat pan (welding shut some holes)
The rear of the frame.This is how it first was:

I first chopped it, then welded the rear and top part with a strap of metal (2mm thick).
The rear fenderThis was probably the most work. I didn't expect this to take so long, but some parts of the rear fender were 4 to 5mm thick.
During the cut:

This is after I cut both sides off and cleaned up the sides a bit. As you can see there are still some holes for the old mounts.

I welded those holes up:

And the hole is gone..

:

Looks neat in my opinion, should give my tire a better look (seeing that it is a whitewall tire I really wanted to show off the entire tire).

I lay the seat pan over the rear of the frame, still have to decide on positioning and obviously I still need to weld brackets for the single shock/suspension into place.

That was it for now. Will order my tires tonight + some other parts.
Fred